Optical observations and dust modelling of comet 156P/Russell-LINEAR

Abstract

Comet 156P/Russell-LINEAR is a short period Jupiter family comet with an orbital period of 6.44 years. The results from spectroscopic, photometric, polarimetric observations, and dust modeling studies are presented here. From the spectroscopic study, strong emissions from 𝐶𝑁(𝛥v = 0), 𝐶3 (𝜆4050 Å), 𝐶2(𝛥v = +1) and 𝐶2(𝛥𝜈 = 0) can be observed during both the epochs of our observations. The Q(𝐶2)/Q(CN) ratio classifies the comet as a typical comet. The imaging data reveals the presence of jets. The dust emission from the comet is observed to have a non-steady-state outflow due to the presence of these strong jets which subside in later epochs, resulting in a steady-state outflow. A polarimetric study at two different phase angles reveals the degree of polarization to be comparable to Jupiter family comets at similar phase angles. Localized variations in polarization values are observed in the coma. The dust modeling studies suggest the presence of high amount of silicate/low absorbing material and indicate the coma to be dominated by higher amount of large size grains with low porosity having power law size distribution index = 2.4. The observed activity and dust propertiespoints to a similarity to another Jupiter family comet, 67P/Churyumo-Gerasimenko.